//The MIT License

//Copyright (c) 2009 Lluis Sanchez, Nick Darnell

//Permission is hereby granted, free of charge, to any person obtaining a copy
//of this software and associated documentation files (the "Software"), to deal
//in the Software without restriction, including without limitation the rights
//to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//copies of the Software, and to permit persons to whom the Software is
//furnished to do so, subject to the following conditions:

//The above copyright notice and this permission notice shall be included in
//all copies or substantial portions of the Software.

//THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//THE SOFTWARE.

using System;
using System.Reflection;
using System.Reflection.Emit;
using Polymorph.Properties;

namespace Polymorph
{
    /// <summary>
    /// The <see cref="CodeThrow"/> class represents a throw statement in
    /// </summary>
    public class CodeThrow : CodeStatement
    {
        private CodeExpression m_exceptionExp;

        /// <summary>
        /// Initializes a new instance of <see cref="CodeThrow"/> with the exception
        /// expression to be thrown.
        /// </summary>
        /// <param name="exceptionExp">The exception expression to throw.</param>
        public CodeThrow(CodeExpression exceptionExp)
        {
            m_exceptionExp = exceptionExp;

            if (!typeof(Exception).IsAssignableFrom(exceptionExp.ResultType))
            {
                throw new ArgumentException(String.Format(Resources.ExpMustHave0Result,
                    "Exception"), "exceptionExp");
            }
        }

        /// <summary>
        /// Generates the IL for the throw statement.
        /// </summary>
        /// <param name="gen">The IL generator to use.</param>
        public override void Generate(ILGenerator gen)
        {
            m_exceptionExp.Generate(gen);
            gen.ThrowException(m_exceptionExp.ResultType);
        }

        /// <summary>
        /// Prints the throw code in a human readable form.
        /// </summary>
        /// <param name="cw">The code writer to use.</param>
        public override void PrintCode(CodeWriter cw)
        {
            cw.Write("throw ");
            m_exceptionExp.PrintCode(cw);
        }
    }
}